. Scientific Frontline: Biology
Showing posts with label Biology. Show all posts
Showing posts with label Biology. Show all posts

Monday, January 30, 2023

Mating causes ‘jet lag’ in female fruit flies, changing behavior

A seminal fluid protein transferred from male to female fruit flies during mating changes the expression of genes related to the fly’s circadian clock, Cornell research has found.
Photo Credit: Erik Karits

A seminal fluid protein transferred from male to female fruit flies during mating changes the expression of genes related to the fly’s circadian clock, an innovative technique has revealed.

The finding, published in the Proceedings of the National Academy of Sciences, could help explain how this protein, called sex peptide, alters the female’s behavior.

Post-mating, sex peptide has been shown to elicit increased egg-laying, aggression, activity and feeding, while reducing sleep and interest in mating in previously unmated females.

“Flies like to eat at certain times of day,” said Mariana Wolfner ’74, professor of molecular biology and genetics and a Stephen H. Weiss Presidential Fellow in the College of Arts and Sciences, and one of the paper’s senior authors. “They sleep at certain times, and the circadian clock machinery controls when flies are likely to do these things.

Saturday, January 28, 2023

Ancestral variation guides future environmental adaptations

A sea campion in its natural habitat on the coast.
Photo Credit: Bangor University

The humble sea campion flower can show us how species adapt.

The speed of environmental change is very challenging for wild organisms. When exposed to a new environment individual plants and animals can potentially adjust their biology to better cope with new pressures they are exposed to - this is known as phenotypic plasticity.

Plasticity is likely to be important in the early stages of colonizing new places or when exposed to toxic substances in the environment. New research published in Nature Ecology & Evolution, shows that early plasticity can influence the ability to subsequently evolve genetic adaptations to conquer new habitats.

Friday, January 27, 2023

Machine learning identifies drugs that could potentially help smokers quit

Penn State College of Medicine researchers helped identify eight medications that may be repurposed to help people quit smoking. A team of more than 70 researchers contributed to the analysis of genetic and smoking behavior data from more than 1.3 million people.
Image Credit: Scientific Frontline

Medications like dextromethorphan, used to treat coughs caused by cold and flu, could potentially be repurposed to help people quit smoking cigarettes, according to a study by Penn State College of Medicine and University of Minnesota researchers. They developed a novel machine learning method, where computer programs analyze data sets for patterns and trends, to identify the drugs and said that some of them are already being tested in clinical trials.

Cigarette smoking is risk factor for cardiovascular disease, cancer and respiratory diseases and accounts for nearly half a million deaths in the United States each year. While smoking behaviors can be learned and unlearned, genetics also plays a role in a person’s risk for engaging in those behaviors. The researchers found in a prior study that people with certain genes are more likely to become addicted to tobacco.

Using genetic data from more than 1.3 million people, Dajiang Liu, Ph.D., professor of public health sciences, and of biochemistry and molecular biology and Bibo Jiang, Ph.D., assistant professor of public health sciences, co-led a large multi-institution study that used machine learning to study these large data sets — which include specific data about a person’s genetics and their self-reported smoking behaviors.

Thursday, January 26, 2023

Rapid plant evolution may make coastal regions more susceptible to flooding and sea level rise

Brady Stiller, University of Notre Dame
Photo Credit: Courtesy University of Notre Dame

Evolution has occurred more rapidly than previously thought in the Chesapeake Bay wetlands, which may decrease the chance that coastal marshes can withstand future sea level rise, researchers at the University of Notre Dame and collaborators demonstrated in a recent publication in Science.

 Jason McLachlan, an associate professor in the Department of Biological Sciences, evaluated the role evolution plays in ecosystems in the Chesapeake Bay by studying a type of grass-like plant, Schoenoplectus americanus, also called chairmaker’s bulrush. The research team used a combination of historical seeds found in core sediment samples, modern plants, and computational models to demonstrate that “resurrected” plants were allocating more resources in their roots below ground, allowing them to store carbon more quickly than modern plants.

Supplementation with amino acid serine eases neuropathy in diabetic mice

From left: Michal Handzlik and Christian Metallo
Photo Credit: Salk Institute

Approximately half of people with type 1 or type 2 diabetes experience peripheral neuropathy—weakness, numbness, and pain, primarily in the hands and feet. The condition occurs when high levels of sugar circulating in the blood damage peripheral nerves. Now, working with mice, Salk Institute researchers, in collaboration with the University of California San Diego, have identified another factor contributing to diabetes-associated peripheral neuropathy: altered amino acid metabolism.

The study, published in Nature, adds to growing evidence that some often-underappreciated, “non-essential” amino acids play important roles in the nervous system. The findings may provide a new way to identify people at high risk for peripheral neuropathy, as well as a potential treatment option. The team included UC San Diego bioengineering professor Prashant Mali, microbiome expert professor Rob Knight and pathologist Nigel A. Calcutt.

“We were surprised that dialing up and down a non-essential amino acid had such a profound effect on metabolism and diabetic complications,” says senior author Christian Metallo, a professor in Salk’s Molecular and Cell Biology Laboratory. “It just goes to show that what we think of as dogma can change under different circumstances, such as in disease conditions.”

Evolutionary Tuning of a Cellular “Powerhouse”

Profiles of the subunits of individual complexes (top) and overall representation of all around 5200 protein signals in MitCOM.
Image Source | Credit: AG Fackler/Pfanner/Becker

Mitochondria are membrane-enclosed structures found in all cells of higher organisms, where they produce most of the necessary energy (“powerhouses of the cell”). In addition, these organelles serve important functions in the synthesis and degradation of certain biomolecules as well as in numerous intercellular signaling processes. In close collaboration, a team of researchers led by Prof. Dr. Nikolaus Pfanner and Prof. Dr. Bernd Fakler from the University of Freiburg Institutes of Biochemistry and Physiology, respectively, and by Prof. Dr. Thomas Becker from the Institute of Biochemistry at the University of Bonn has now applied a newly developed analytical method to comprehensively map the structural organization of proteins in mitochondria. The results provide initial insight into the structure and organization of the mitochondrial proteins in protein machineries of varying complexity, thus laying the foundation for future studies of new protein functions and structures. This study was published in the journal Nature.

Comprehensive picture of the composition of protein complexes indispensable

Mechanical forces in the nervous system play a corrective role

The researchers visualized the forces acting on dendrites during pruning by measuring their lengths (blue/red) and the angles at dendritic branchpoints: A) before, B) after dendrite severing,
Image Credit: WWU - Rumpf Lab

Researchers at Münster University show in the fruit fly how mechanical tearing cuts neural connections

Nerve cells communicate with one another via long processes known as axons and dendrites, or, more generally, neurites. During development, these processes first grow and form connections with other cells, for example synapses with other nerve cells. Any neurites which are not properly linked, or are no longer needed, are removed by a corrective mechanism known as “pruning”. Such pruning processes can appear drastic, and neurites sometimes seem to be severed directly from the nerve cell. Researchers headed by Dr. Sebastian Rumpf from the Institute of Neuro- and Behavioral Biology at Münster University has now found the mechanism of neurite severing. In a study published in the Journal of Cell Biology, the team show that in sensory nerve cells of the fruit fly Drosophila melanogaster, pruning occurs through mechanical tearing.

Power of cancer drugs may see boost by targeting newly identified pathway

Proteins labeled with colored tags fill the main compartment — but not the nuclei (blue) — of human cervical cancer cells. Green cells contain the protein TRPV2, red cells contain STING, and yellow and orange cells contain a mixture of both. The proteins are part of a newly discovered DNA-protection pathway that potentially could be targeted to improve cancer therapies, according to researchers at Washington University School of Medicine in St. Louis.
Image Credit: Lingzhen Kong

Cells zealously protect the integrity of their genomes, because damage can lead to cancer or cell death. The genome — a cell’s complete set of DNA — is most vulnerable while it is being duplicated before a cell divides. Cancer cells constantly are dividing, so their genomes are constantly in jeopardy.

Researchers at Washington University School of Medicine in St. Louis has identified a previously unknown signaling pathway cells use to protect their DNA while it is being copied. The findings, published in the journal Molecular Cell, suggest that targeting this pathway potentially could boost the potency of cancer therapeutics.

“A cell that can’t protect its genome is going to die,” said senior author Zhongsheng You, a professor of cell biology and physiology. “This entire pathway we found exists to protect the genome so the cell can survive in the face of replication stress. By combining inhibitors of this pathway with chemotherapy drugs that target the DNA replication process, we potentially could make such drugs more effective.”

Pioneering approach advances study of CTCF protein in transcription biology

Scientists at St. Jude collaborated to better understand CTCF. L to R: Beisi Xu, PhD, Chunliang Li, PhD; Judith Hyle; Mohamed Nadhir Djekidel, PhD.
Photo Credit: St. Jude Children's Research Hospital

Scientists at St. Jude Children’s Research Hospital used the auxin-inducible degron 2 system on CTCF, bringing the novel approach to bear on a fundamental protein.

CTCF is a critical protein known to play various roles in key biological processes such as transcription. Scientists at St. Jude Children’s Research Hospital used a next-generation protein degradation technology to study CTCF. Their work revealed the superiority of the approach in addition to providing functional insights into how CTCF regulates transcription. The study, published today in Genome Biology, paves the way for more clear, nuanced studies of CTCF.

Transcription is an essential biological process where DNA is copied into RNA. The process is the first required step in a cell to take the instructions housed in DNA and ultimately translate that code into the amino acid or polypeptide building blocks that become active proteins. Dysregulated transcription plays a role in many types of pediatric cancer. Finding ways to modify or target aspects of the transcriptional machinery is a novel frontier in the search for vulnerabilities that can be exploited therapeutically.

While the biology of CTCF has been extensively studied, how the different domains (parts) of CTCF function in relation to transcription regulation remains unclear.

Mimicking an Enigmatic Property of Circadian Rhythms through an Artificial Chemical Clock


An innovative temperature-compensation mechanism for oscillating chemical reactions based on temperature-responsive gels has been recently reported by researchers at Tokyo Tech. Their experimental findings, alongside a detailed mathematical analysis, hint at the possibility that circadian rhythms found in nature may all rely on a similar mechanism, allowing their period to remain independent of temperature.

Circadian rhythms are natural, internal oscillations that synchronize an organism's behaviors and physiological processes with their environment. These rhythms normally have a period of 24 hours and are regulated by internal chemical clocks that respond to cues from outside the body, such as light.

Although well studied in animals, plants, and bacteria, circadian rhythms all share an enigmatic property—the oscillation period is not significantly affected by temperature, even though the rate of most biochemical reactions changes exponentially with temperature. This clearly indicates that some sort of temperature-compensation mechanism is at play. Interestingly, some scientists have managed to replicate such temperature-invariant qualities in certain oscillating chemical reactions. However, these reactions are often troublesome and require extremely precise adjustments on the reacting chemicals.

Motile Sperm and Frequent Abortions in Spreading Earth moss

The protein PINC has an influence on the motility of sperm cells (left) and the anchoring of spore capsules (right, dark structures) in the moss Physcomitrella. The fluorescence microscope images in the middle show the male sex organ on the left and a young spore capsule on the right. PINC is marked in magenta.
Image Credit: Volker Lüth / University of Freiburg

Freiburg researchers discover that sperm motility and anchoring of the spore capsule in the spreading earth moss Physcomitrella are influenced by the auxin transporter PINC.

As a component of moors, mosses are important for climate conservation. They are also gaining increasing significance in biotechnology and the manufacture of biopharmaceuticals. For the most varied of rationales, mosses are interesting research objects. One reason for this is because they are particularly similar to the first land plants. As a result, they provide insight into the original function of signaling molecules which regulate growth and development in all land plants today. Researchers at the University of Freiburg and the Excellence Cluster CIBSS – Centre for Integrative Biological Signaling Studies – have discovered that transporters of the hormone auxin influence the fertility of spreading earth moss. Their observations have been published in the scientific journal New Phytologist.

Wednesday, January 25, 2023

Probe can measure both cell stiffness and traction, researchers report

Professor Ning Wang, front right, is joined by researchers, from left, Fazlur Rashid, Kshitij Amar and Parth Bhala.
Photo Credit: Fred Zwicky

Scientists have developed a tiny mechanical probe that can measure the inherent stiffness of cells and tissues as well as the internal forces the cells generate and exert on one another. Their new “magnetic microrobot” is the first such probe to be able to quantify both properties, the researchers report, and will aid in understanding cellular processes associated with development and disease.

They detail their findings in the journal Science Robotics.

“Living cells generate forces through protein interactions, and it’s very hard to measure these forces,” said Ning Wang, a professor of mechanical science and engineering at the University of Illinois Urbana-Champaign who led the research. “Most probes can either measure the forces actively generated by the tissues and cells themselves, a trait we call traction, or they can measure their stiffness – but not both.”

To measure cell stiffness, researchers need a relatively rigid probe that can compress, stretch or twist the tissues and quantify how robustly they resist. But to measure the cells’ own internally generated contractions or expansions, a probe must be relatively soft and supple.

Like other scientists, Wang and his colleagues had already developed probes to measure each of these qualities individually. But he said he wanted to develop a more universal probe that could tackle both at once. Such a probe would allow a better understanding of how these properties influence diseases like arteriosclerosis or cancer, or how an embryo develops, for example.

Wolves eliminate deer on Alaskan Island then quickly shift to eating sea otters


Wolves on an Alaskan island caused a deer population to plummet and switched to primarily eating sea otters in just a few years, a finding scientists at Oregon State University and the Alaska Department of Fish and Game believe is the first case of sea otters becoming the primary food source for a land-based predator.

Using methods such as tracking the wolves with GPS collars and analyzing their scat, the researchers found that in 2015 deer were the primary food of the wolves, representing 75% of their diet, while sea otters comprised 25%. By 2017, wolves transitioned to primarily consuming sea otters (57% of their diet) while the frequency of deer declined to 7%. That pattern held through 2020, the end of the study period.

“Sea otters are this famous predator in the near-shore ecosystem and wolves are one of the most famous apex predators in terrestrial systems,” said Taal Levi, an associate professor at Oregon State. “So, it’s pretty surprising that sea otters have become the most important resource feeding wolves. You have top predators feeding on a top predator.”

Tuesday, January 24, 2023

Stress may trigger male defense against predators

Photo Credit: Jörgen Wiklund

Only males among the fish species crucian carp have developed a strategy to protect themselves from hungry predators, according to a new study from Lund University in Sweden. The explanation could lie in that the surrounding environment affects the stress system in males and females differently.

Some animals have evolved the ability to swiftly change appearance to defend themselves against predators when necessary - while avoiding the unnecessary costs of that appearance when it is not needed. This is an advantage for animals that live in environments where the risk of being eaten by predators varies. However, there is a difference in the ability of females and males to escape the enemy in this way. Researchers at Lund University have investigated the crucian carp fish species.

“When the smell of predatory fish spreads in the water, the male crucian carp begins to change its appearance, much like a character from Transformers. From having grown in length, the presence of the predatory fish causes the male carp to instead grow in height. The new body shape makes it much more difficult for gape-size limited predators to swallow them. The shape also provides better acceleration, which is an advantage when the fish has to escape from an attacking pike”, explains Jerker Vinterstare, biologist at Lund University.

Genes Common to Different Species Found to Be Connected to the Development of Depression

Affective disorders, also known as mood disorders, are a group of mental illnesses that involve changes in emotional states.
Photo Credit:: Christopher Lemercier

Russian scientists performed a cross-species analysis of brain gene expression in danio fish, rats and humans to identify new common molecular targets for the therapy of affective disorders of the central nervous system induced by chronic stress. The study was able to identify several key brain proteins that may play important roles in the pathogenesis of affective disorders.

The article was published in the journal Scientific Reports. Affective disorders, also known as mood disorders, are a group of mental illnesses that involve changes in emotional states. They include various forms of depression and mania, psychosis, and increased anxiety. They are widespread because they occur not only as independent mental pathologies, but also as complications of neurological and other somatic diseases.

This fact determines the difficulty of diagnosis: people classify low mood, anxiety and irritability as temporary, situational manifestations. According to statistics, emotional disorders of varying severity occur in 20% of people, but only a quarter of them receive qualified help.

Monday, January 23, 2023

Mutant with Counting Disability

Stimulation of the Venus flytrap by touch triggers electrical signals and calcium waves. The calcium signature is decoded; this causes the trap to shut quickly. The DYSC mutant has lost the ability to read and decode the calcium signature correctly.
Image Credit: Ines Kreuzer / Universität Würzburg

The newly discovered dyscalculia mutant of the Venus flytrap has lost its ability to count electrical impulses. Würzburg researchers reveal the cause of the defect.

The carnivorous Venus flytrap (Dionaea muscipula) can count to five: This discovery by Würzburg biophysicist Professor Rainer Hedrich caused worldwide excitement in 2016. How does the plant count? Hedrich's team from Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany, has now described the key component in the journal Current Biology. The researchers found what they were looking for in a mutant of the Venus flytrap that has lost its counting abilities.

Anti-aging gene shown to rewind heart age by 10 years

Centenarian
Photo Credit: Mehmet Turgut Kirkgoz

An anti-aging gene discovered in a population of centenarians has been shown to rewind the heart’s biological age by ten years. The breakthrough, published in Cardiovascular Research and led by scientists at the University of Bristol and the MultiMedica Group in Italy, offers a potential target for patients with heart failure.

Associated with exceptional longevity, carriers of healthy mutant genes, like those living in blue zones of the planet, often live to 100 years or more and remain in good health. These individuals are also less prone to cardiovascular complications. Scientists funded by the British Heart Foundation believe the gene helps to keep their hearts young by protecting them against diseases linked to aging, such as heart failure.

In this new study, researchers demonstrate that one of these healthy mutant genes, previously proved particularly frequent in centenarians, can protect cells collected from patients with heart failure requiring cardiac transplantation.

Avian flu could decimate Australian black swans

Australian black swan
UQ research shows black swans lack some immune genes which help other wild waterfowl combat avian flu.
Photo Credit: Holger Detje

The unique genetics of the Australian black swan leaves the species vulnerable to viral illnesses such as avian flu, University of Queensland research has revealed.

The UQ-led study has generated a first-ever genome of the black swan which revealed the species lacks some immune genes which help other wild waterfowl combat infectious diseases.

Associate Professor Kirsty Short from UQ’s School of Chemistry and Molecular Biosciences said the geographic isolation of Australia’s black swans has meant limited exposure to pathogens commonly found in other parts of the world leading to reduced immune diversity.

“Unlike Mallard ducks for example, black swans are extremely sensitive to highly pathogenic avian influenza – HPAI which is often referred to as bird flu - and can die from it within three days,” Dr Short said.

Sunday, January 22, 2023

Stanford Medicine researchers measure thousands of molecules from a single drop of blood

A single drop of blood can yield measurements for thousands of proteins, fats and other biomarkers, researchers at Stanford Medicine found.
Photo Credit: PublicDomainPictures

Researchers at Stanford Medicine have shown they can measure thousands of molecules — some of which are signals of health — from a single drop of blood.

The new approach combines a microsampling device — a tool used to self-administer a finger prick — with “multi-omics” technologies, which simultaneously analyze a vast array of proteins, fats, by-products of metabolism and inflammatory markers.

“Even more importantly, we’ve shown you can collect the blood drop at home and mail it into the lab,” said Michael Snyder, PhD, director of the Center for Genomics and Personalized Medicine and senior author on the research, which was published in Nature Biomedical Engineering on Jan. 19.

Unlike finger-prick testing for diabetes, which measures a single type of molecule (glucose), multi-omics microsampling gives data about thousands of different molecules at once.

The research sounds similar to a well-known approach promoted in the past for testing a single drop of blood, but there are important differences: While the earlier approach was based on replicating existing diagnostic tests, multi-omic microsampling uses a different type of data analysis based on a technology called mass spectrometry, which sorts molecules based on their mass and electronic charge. In addition, the data analysis is performed in a lab, not in a portable box.

Wednesday, January 18, 2023

Harnessing the healing power within our cells

E. coli bacteria
Photo Credit: Public Domain 

University of Queensland researchers have identified a pathway in cells that could be used to reprogram the body’s immune system to fight back against both chronic inflammatory and infectious diseases.

Dr Kaustav Das Gupta and Professor Matt Sweet from UQ’s Institute for Molecular Bioscience discovered that a molecule derived from glucose in immune cells can both stop bacteria growing and dampen inflammatory responses.

Dr Das Gupta said the finding is a critical step towards future therapeutics that train immune cells.

“The effects of this molecule called ribulose-5-phosphate on bacteria are striking – it can cooperate with other immune factors to stop disease-causing strains of the E. coli bacteria from growing,” Dr Das Gupta said.

“It also reprograms the immune system to switch off destructive inflammation, which contributes to both life-threatening infectious diseases such as sepsis as well as chronic inflammatory diseases like respiratory diseases, chronic liver disease, inflammatory bowel disease, rheumatoid arthritis, heart disease, stroke, diabetes and dementia.”

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